1. Field of the Invention
The present invention relates to an optical navigation apparatus and an optical navigation method. More particularly, the present invention relates to an optical navigation apparatus and an optical navigation method that are capable of adjusting the displacement resolution.
2. Descriptions of the Related Art
Computer mice are used as primary input devices for conventional computer peripheral devices. Users often use the computer mouse to move a cursor shown on a monitor, or even use the computer mouse to select the desired options, applications, etc. Therefore, computer mice have become an important bridge for communication between users and computers. Accordingly, computer mice that adopt various technologies have been developed by manufacturers. Particularly, over recent years, optical navigation apparatuses, such as Optical Finger Mice (OFMs) have also been developed.
Such optical navigation apparatuses operate in the following principle: a beam of light is projected by a light source unit to a touch object (e.g., a reflective surface or a finger), the images are captured by an image sensing unit, and then a cursor shown on the monitor is controlled according to a piece of displacement information derived from the images. Since conventional optical navigation apparatuses have an invariable displacement resolution, operational errors tend to occur when the operation scenario or the operation varies. For example, when the cursor shown on the monitor has been moved to a target that is to be selected by the user, the user must use the optical navigation apparatus again to select the target through clicking. However, when clicking the target, the user's finger will not only move in the vertical direction but also often move in the horizontal direction, which might cause the cursor shown on the monitor to move towards a different position to result in a false click operation.
Accordingly, there is an urgent need in the art to provide an optical navigation apparatus that is capable of adjusting the displacement resolution adaptively according to the different operations of the user.